LCM of 4 and 15
LCM of 4 and 15 is the smallest number among all common multiples of 4 and 15. The first few multiples of 4 and 15 are (4, 8, 12, 16, 20, 24, . . . ) and (15, 30, 45, 60, 75, 90, 105, . . . ) respectively. There are 3 commonly used methods to find LCM of 4 and 15 - by prime factorization, by division method, and by listing multiples.
1. | LCM of 4 and 15 |
2. | List of Methods |
3. | Solved Examples |
4. | FAQs |
What is the LCM of 4 and 15?
Answer: LCM of 4 and 15 is 60.
Explanation:
The LCM of two non-zero integers, x(4) and y(15), is the smallest positive integer m(60) that is divisible by both x(4) and y(15) without any remainder.
Methods to Find LCM of 4 and 15
Let's look at the different methods for finding the LCM of 4 and 15.
- By Division Method
- By Listing Multiples
- By Prime Factorization Method
LCM of 4 and 15 by Division Method
To calculate the LCM of 4 and 15 by the division method, we will divide the numbers(4, 15) by their prime factors (preferably common). The product of these divisors gives the LCM of 4 and 15.
- Step 1: Find the smallest prime number that is a factor of at least one of the numbers, 4 and 15. Write this prime number(2) on the left of the given numbers(4 and 15), separated as per the ladder arrangement.
- Step 2: If any of the given numbers (4, 15) is a multiple of 2, divide it by 2 and write the quotient below it. Bring down any number that is not divisible by the prime number.
- Step 3: Continue the steps until only 1s are left in the last row.
The LCM of 4 and 15 is the product of all prime numbers on the left, i.e. LCM(4, 15) by division method = 2 × 2 × 3 × 5 = 60.
LCM of 4 and 15 by Listing Multiples
To calculate the LCM of 4 and 15 by listing out the common multiples, we can follow the given below steps:
- Step 1: List a few multiples of 4 (4, 8, 12, 16, 20, 24, . . . ) and 15 (15, 30, 45, 60, 75, 90, 105, . . . . )
- Step 2: The common multiples from the multiples of 4 and 15 are 60, 120, . . .
- Step 3: The smallest common multiple of 4 and 15 is 60.
∴ The least common multiple of 4 and 15 = 60.
LCM of 4 and 15 by Prime Factorization
Prime factorization of 4 and 15 is (2 × 2) = 22 and (3 × 5) = 31 × 51 respectively. LCM of 4 and 15 can be obtained by multiplying prime factors raised to their respective highest power, i.e. 22 × 31 × 51 = 60.
Hence, the LCM of 4 and 15 by prime factorization is 60.
☛ Also Check:
- LCM of 11 and 18 - 198
- LCM of 16, 20 and 24 - 240
- LCM of 20, 30 and 40 - 120
- LCM of 45 and 60 - 180
- LCM of 4, 7 and 10 - 140
- LCM of 12, 15, 20 and 54 - 540
- LCM of 12 and 25 - 300
LCM of 4 and 15 Examples
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Example 1: Find the smallest number that is divisible by 4 and 15 exactly.
Solution:
The smallest number that is divisible by 4 and 15 exactly is their LCM.
⇒ Multiples of 4 and 15:- Multiples of 4 = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, . . . .
- Multiples of 15 = 15, 30, 45, 60, 75, . . . .
Therefore, the LCM of 4 and 15 is 60.
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Example 2: The GCD and LCM of two numbers are 1 and 60 respectively. If one number is 15, find the other number.
Solution:
Let the other number be m.
∵ GCD × LCM = 15 × m
⇒ m = (GCD × LCM)/15
⇒ m = (1 × 60)/15
⇒ m = 4
Therefore, the other number is 4. -
Example 3: The product of two numbers is 60. If their GCD is 1, what is their LCM?
Solution:
Given: GCD = 1
product of numbers = 60
∵ LCM × GCD = product of numbers
⇒ LCM = Product/GCD = 60/1
Therefore, the LCM is 60.
The probable combination for the given case is LCM(4, 15) = 60.
FAQs on LCM of 4 and 15
What is the LCM of 4 and 15?
The LCM of 4 and 15 is 60. To find the LCM of 4 and 15, we need to find the multiples of 4 and 15 (multiples of 4 = 4, 8, 12, 16 . . . . 60; multiples of 15 = 15, 30, 45, 60) and choose the smallest multiple that is exactly divisible by 4 and 15, i.e., 60.
What is the Least Perfect Square Divisible by 4 and 15?
The least number divisible by 4 and 15 = LCM(4, 15)
LCM of 4 and 15 = 2 × 2 × 3 × 5 [Incomplete pair(s): 3, 5]
⇒ Least perfect square divisible by each 4 and 15 = LCM(4, 15) × 3 × 5 = 900 [Square root of 900 = √900 = ±30]
Therefore, 900 is the required number.
How to Find the LCM of 4 and 15 by Prime Factorization?
To find the LCM of 4 and 15 using prime factorization, we will find the prime factors, (4 = 2 × 2) and (15 = 3 × 5). LCM of 4 and 15 is the product of prime factors raised to their respective highest exponent among the numbers 4 and 15.
⇒ LCM of 4, 15 = 22 × 31 × 51 = 60.
If the LCM of 15 and 4 is 60, Find its GCF.
LCM(15, 4) × GCF(15, 4) = 15 × 4
Since the LCM of 15 and 4 = 60
⇒ 60 × GCF(15, 4) = 60
Therefore, the GCF (greatest common factor) = 60/60 = 1.
What is the Relation Between GCF and LCM of 4, 15?
The following equation can be used to express the relation between GCF and LCM of 4 and 15, i.e. GCF × LCM = 4 × 15.
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